Generation of Hydrogen Reactive Species For Processing of Workpieces

ABSTRACT

Methods, systems, and apparatus for generating hydrogen radicals for processing a workpiece, such as a semiconductor workpiece, are provided. In one example implementation, a method can include generating one or more species in a plasma chamber from an inert gas by inducing a plasma in the inert gas using a plasma source; mixing hydrogen gas with the one or more species to generate one or more hydrogen radicals; and exposing the workpiece in a processing chamber to the one or more hydrogen radicals.

PRIORITY CLAM

The present application claims the benefit of priority of U.S.Provisional Application Ser. No. 62/683,246 titled “Generation ofHydrogen Reactive Species for Processing of Workpieces,” filed on Jun.11, 2018, which is incorporated herein by reference for all purposes.

FIELD

The present disclosure relates generally to generation of hydrogenreactive species for processing of workpieces using, for instance, aplasma processing apparatus.

BACKGROUND

In semiconductor processing, device dimension and materials thicknesscontinue to decrease with shrinking critical dimension in semiconductordevices. In advanced device nodes, materials surface properties andinterface integrity become increasingly important to device performance.

SUMMARY

Aspects and advantages of embodiments of the present disclosure will beset forth in part in the following description, or may be learned fromthe description, or may be learned through practice of the embodiments.

One example aspect of the present disclosure is directed to a method forprocessing a workpiece. The method can include generating one or morespecies in a plasma chamber from an inert gas by inducing a plasma inthe inert gas using a plasma source. The method can include mixinghydrogen gas with the one or more species to generate one or morehydrogen radicals. The method can include exposing the workpiece in aprocessing chamber to the one or more hydrogen radicals.

These and other features, aspects and advantages of various embodimentswill become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the present disclosure and, together with thedescription, serve to explain the related principles.

BRIEF DESCRIPTION OF THE DRAWINGS

Detailed discussion of embodiments directed to one of ordinary skill inthe art are set forth in the specification, which makes reference to theappended figures, in which:

FIG. 1 depicts an example plasma processing apparatus according toexample embodiments of the present disclosure;

FIG. 2 depicts a flow diagram of an example method according to exampleembodiments of the present disclosure;

FIG. 3 depicts example mixing of a hydrogen gas with one or more speciesgenerated from an inert gas according to example embodiments of thepresent disclosure;

FIG. 4 depicts example mixing of a hydrogen gas with one or more speciesgenerated from an inert gas according to example embodiments of thepresent disclosure;

FIG. 5 depicts an example plasma processing apparatus according toexample embodiments of the present disclosure; and

FIG. 6 depicts an example plasma processing apparatus according toexample embodiments of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments, one or moreexamples of which are illustrated in the drawings. Each example isprovided by way of explanation of the embodiments, not limitation of thepresent disclosure. In fact, it will be apparent to those skilled in theart that various modifications and variations can be made to theembodiments without departing from the scope or spirit of the presentdisclosure. For instance, features illustrated or described as part ofone embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that aspects of the presentdisclosure cover such modifications and variations.

Example aspects of the present disclosure are directed to generation ofhydrogen radicals for processing of a workpiece, such as a semiconductorworkpiece. Hydrogen radicals have various applications in semiconductorprocessing. For instance, at low temperature, hydrogen radicals canremove photoresist or other polymer materials effectively with reducedunderlying materials damage and/or oxidation. At high temperature,hydrogen radicals can selectively etch damaged silicon materials (e.g.for silicon fin trimming in three-dimensional FINFET structures).

Hydrogen radicals can be generated, for instance, by passing a hydrogengas through a hot wire (e.g., a tungsten hot wire). Hydrogen radicalscan be generated, for instance, using capacitive and/or inductive plasmasources. For instance, hydrogen radicals can be generated from a processgas using an inductively coupled plasma source in a remote plasmachamber. Ion filtering can be implemented, for instance, using agrounded separation grid to reduce ions generated in the plasma andallow neutral hydrogen radicals to pass through the grid. The grid canhave a distribution of holes to facilitate control of radicaldistribution. Energy of the hydrogen radicals can be controlled, forinstance, using pulsed RF power applied to the power source and/or viapost-plasma modification (e.g., mixing of other gases).

According to example embodiments, an inert gas (e.g., helium, argon,xenon, neon, etc.) can be activated using a plasma source in a plasmachamber to generate excited species from the inert gas. A hydrogen gascan be mixed with the excited species (e.g., outside of the plasmachamber, such as downstream of the plasma chamber) to generate one ormore hydrogen radicals. The hydrogen radicals can be exposed to aworkpiece (e.g., in a processing chamber) to implement varioussemiconductor fabrication processes.

In some embodiments, the method can include generating one or moreexcited inert gas molecules (e.g., excited He molecules) in a plasmachamber that is separated from a processing chamber by a separationgrid. The excited inert gas molecules can be generated, for instance, byinducing a plasma in a process gas using a plasma source (e.g.,inductive plasma source, capacitive plasma source, etc.). The processgas can be an inert gas. For instance, the process gas can be helium,argon, xenon, neon, or other inert gas. In some embodiments, the processgas can consist of an inert gas.

The method can include filtering ions while allowing the passage ofneutral species to generate a filtered mixture with neutral radicals forexposure to the workpiece. For instance, a separation grid can be usedto filter ions generated in the plasma chamber and allow passage ofneutral species through holes in the separation grid to the processingchamber for exposure to the workpiece.

In some embodiments, the hydrogen radicals can be generated by mixinghydrogen gas (H₂) with the excited species at or below (e.g.,downstream) of the separation grid. For instance, in some embodiments,the separation grid can have a plurality of grid plates. The hydrogengas can be injected into species passing through the separation grid ata location below or downstream of one of the grid plates. In someembodiments, the hydrogen gas can be injected into species passingthrough the separation grid at a location between two grid plates. Insome embodiments, the hydrogen gas can be injected into the species at alocation beneath all of the grid plates (e.g., in the processingchamber).

Mixing the hydrogen gas with the excited species from the inert gas canresult in the generation of one or more hydrogen radicals, such asneutral hydrogen radicals. The hydrogen radicals can be exposed to aworkpiece in the processing chamber.

In some embodiments, the workpiece can be supported on a pedestal orworkpiece support. The pedestal or workpiece support can include atemperature regulation system (e.g., one or more electrical heaters)used to control a temperature of the workpiece temperature duringprocessing. In some embodiments, process can be carried out with theworkpiece at a temperature in the range of about 20° C. to about 500° C.

The hydrogen radicals can be exposed to a workpiece in the processingchamber for implementation of a variety of different semiconductorfabrication processes. For example, the hydrogen radicals can be usedfor removal of a photoresist layer on the workpiece. As another example,the hydrogen radicals can be used to remove a residual (e.g., residualorganic) on the workpiece to clean the workpiece. As another example,the hydrogen radicals can be used to assist with silicon atom mobilityand smoothing of the workpiece surface (e.g., at high temperatures suchas temperatures greater than about 400° C.). As another example, thehydrogen radicals can be used to at least partially remove a damagedsilicon layer on the workpiece. As yet another example, the hydrogenradicals can be used to remove a suboxide layer on the workpiece. Thehydrogen radicals can be used to implement other semiconductor processapplications without deviating from the scope of the present disclosure.

In some embodiments, a metal-containing gas can be mixed with the one ormore hydrogen radicals to facilitate deposition of a thin metal film onthe workpiece. In some embodiments, the metal can be titanium. In someembodiments, the metal can be tantalum. In some embodiments, the metalcan be aluminum.

Aspects of the present disclosure are discussed with reference to a“wafer” or semiconductor wafer for purposes of illustration anddiscussion. Those of ordinary skill in the art, using the disclosuresprovided herein, will understand that the example aspects of the presentdisclosure can be used in association with any semiconductor substrateor other suitable substrate. “Downstream” in reference to a plasmachamber refers to a location in plasma processing apparatus that isexposed to species generated in the plasma chamber, such as a locationoutside the plasma chamber that is exposed to species generated in theplasma chamber. In addition, the use of the term “about” in conjunctionwith a numerical value is intended to refer to within ten percent (10%)of the stated numerical value. A “pedestal” refers to any structure thatcan be used to support a workpiece.

FIG. 1 depicts an example plasma processing apparatus 100 that can beused to perform processes according to example embodiments of thepresent disclosure. As illustrated, plasma processing apparatus 100includes a processing chamber 110 and a plasma chamber 120 that isseparated from the processing chamber 110. Processing chamber 110includes a substrate holder or pedestal 112 operable to hold a workpiece114 to be processed, such as a semiconductor wafer. In this exampleillustration, a plasma is generated in plasma chamber 120 (i.e., plasmageneration region) by an inductively coupled plasma source 135 anddesired species are channeled from the plasma chamber 120 to the surfaceof workpiece 114 through a separation grid assembly 200.

Aspects of the present disclosure are discussed with reference to aninductively coupled plasma source for purposes of illustration anddiscussion. Those of ordinary skill in the art, using the disclosuresprovided herein, will understand that any plasma source (e.g.,inductively coupled plasma source, capacitively coupled plasma source,etc.) can be used without deviating from the scope of the presentdisclosure.

The plasma chamber 120 includes a dielectric side wall 122 and a ceiling124. The dielectric side wall 122, ceiling 124, and separation grid 200define a plasma chamber interior 125. Dielectric side wall 122 can beformed from a dielectric material, such as quartz and/or alumina. Theinductively coupled plasma source 135 can include an induction coil 130disposed adjacent the dielectric side wall 122 about the plasma chamber120. The induction coil 130 is coupled to an RF power generator 134through a suitable matching network 132. Process gases (e.g., an inertgas) can be provided to the chamber interior from gas supply 150 andannular gas distribution channel 151 or other suitable gas introductionmechanism. When the induction coil 130 is energized with RF power fromthe RF power generator 134, a plasma can be generated in the plasmachamber 120. In a particular embodiment, the plasma processing apparatus100 can include an optional grounded Faraday shield 128 to reducecapacitive coupling of the induction coil 130 to the plasma.

As shown in FIG. 1, a separation grid 200 separates the plasma chamber120 from the processing chamber 110. The separation grid 200 can be usedto perform ion filtering from a mixture generated by plasma in theplasma chamber 120 to generate a filtered mixture. The filtered mixturecan be exposed to the workpiece 114 in the processing chamber.

In some embodiments, the separation grid 200 can be a multi-plateseparation grid. For instance, the separation grid 200 can include afirst grid plate 210 and a second grid plate 220 that are spaced apartin parallel relationship to one another. The first grid plate 210 andthe second grid plate can be separated by a distance.

The first grid plate 210 can have a first grid pattern having aplurality of holes. The second grid plate 220 can have a second gridpattern having a plurality of holes. The first grid pattern can be thesame as or different from the second grid pattern. Charged particles canrecombine on the walls in their path through the holes of each gridplate 210, 220 in the separation grid. Neutral species (e.g., radicals)can flow relatively freely through the holes in the first grid plate 210and the second grid plate 220. The size of the holes and thickness ofeach grid plate 210 and 220 can affect transparency for both charged andneutral particles.

In some embodiments, the first grid plate 210 can be made of metal(e.g., aluminum) or other electrically conductive material and/or thesecond grid plate 220 can be made from either an electrically conductivematerial or dielectric material (e.g., quartz, ceramic, etc.). In someembodiments, the first grid plate 210 and/or the second grid plate 220can be made of other materials, such as silicon or silicon carbide. Inthe event a grid plate is made of metal or other electrically conductivematerial, the grid plate can be grounded.

FIG. 2 depicts a flow diagram of an example method (300) according toexample aspects of the present disclosure. The method (300) can beimplemented using the plasma processing apparatus 100. However, as willbe discussed in detail below, the methods according to example aspectsof the present disclosure can be implemented using other approacheswithout deviating from the scope of the present disclosure. FIG. 2depicts steps performed in a particular order for purposes ofillustration and discussion. Those of ordinary skill in the art, usingthe disclosures provided herein, will understand that various steps ofany of the methods described herein can be omitted, expanded, performedsimultaneously, rearranged, and/or modified in various ways withoutdeviating from the scope of the present disclosure. In addition, variousadditional steps (not illustrated) can be performed without deviatingfrom the scope of the present disclosure.

At (302), the method can include heating the workpiece. For instance,the workpiece 114 can be heated in the processing chamber to a processtemperature. The workpiece 114 can be heated, for instance, using one ormore heating systems associated with the pedestal 112. In someembodiments, the workpiece can be heated to a process temperature in therange of about 20° C. to about 500° C., such as about 400° C. or anyother temperature or range of temperatures therebetween.

At (304), the method can include admitting a process gas (e.g., an inertgas) into the plasma chamber. For instance, a process gas can beadmitted into the plasma chamber interior 125 from a gas source 150 viaannular gas distribution channel 151 or other suitable gas introductionmechanism. The process gas can be an inert gas, such as an inert gaswith no reactive gas. For instance, the process gas can consist of theinert gas. The process gas can be, for instance, helium, argon, xenon,neon or other inert gas.

At (306), the method can include energizing an inductively coupledplasma source to generate a plasma in a plasma chamber. For instance,induction coil 130 can be energized with RF energy from RF powergenerator 134 to generate a plasma in the plasma chamber interior 125.In some embodiments, the inductively coupled power source can beenergized with pulsed power to obtain species with desired plasmaenergy. At (308), the plasma can be used to generate one or more species(e.g., excited inert gas molecules) from the process gas.

At (310), the method can include filtering one or more ions generated bythe plasma in the mixture to create a filtered mixture. The filteredmixture can include species (e.g., excited inert gas molecules, etc.)generated by the plasma in the process gas. In some embodiments, the oneor more ions can be filtered using a separation grid assembly separatingthe plasma chamber from a processing chamber where the workpiece islocated. For instance, separation grid 200 can be used to filter ionsgenerated by the plasma.

The separation grid 200 can have a plurality of holes. Charged particles(e.g., ions) can recombine on the walls in their path through theplurality of holes. Neutral particles (e.g., radicals) can pass throughthe holes. In some embodiments, the separation grid 200 can beconfigured to filter ions with an efficiency greater than or equal toabout 90%, such as greater than or equal to about 95%.

In some embodiments, the separation grid can be a multi-plate separationgrid. The multi-plate separation grid can have multiple separation gridplates in parallel. The arrangement and alignment of holes in the gridplate can be selected to provide a desired efficiency for ion filtering,such as greater than or equal to about 95%.

At (312), the method can include mixing hydrogen (e.g., H₂ gas) with thespecies to generate one or more hydrogen radicals. The hydrogen can bemixed with the species by injecting a gas into post plasma mixtures(e.g., at or below a separation grid).

FIG. 3 depicts an example separation grid 200 for injection of hydrogenpost plasma according to example embodiments of the present disclosure.More particularly, the separation grid 200 includes a first grid plate210 and a second grid plate 220 disposed in parallel relationship. Thefirst grid plate 210 and the second grid plate 220 can provide forion/UV filtering.

The first grid plate 210 and a second grid plate 220 can be in parallelrelationship with one another. The first grid plate 210 can have a firstgrid pattern having a plurality of holes. The second grid plate 220 canhave a second grid pattern having a plurality of holes. The first gridpattern can be the same as or different from the second grid pattern.Species (e.g., excited inert gas molecules) 215 from the plasma can beexposed to the separation grid 200. Charged particles (e.g., ions) canrecombine on the walls in their path through the holes of each gridplate 210, 220 in the separation grid 200. Neutral species (e.g.,excited inert gas molecules) can flow relatively freely through theholes in the first grid plate 210 and the second grid plate 220.

Subsequent to the second grid plate 220, a gas injection source 230 canbe configured to mix hydrogen 232 into the species passing through theseparation grid 200. A mixture 225 including hydrogen radicals resultingfrom the injection of hydrogen gas can pass through a third grid plate235 for exposure to the workpiece in the processing chamber.

The present example is discussed with reference to a separation gridwith three grid plates for example purposes. Those of ordinary skill inthe art, using the disclosures provided herein, will understand thatmore or fewer grid plates can be used without deviating from the scopeof the present disclosure. In addition, the hydrogen can be mixed withthe species at any point in the separation grid and/or after theseparation grid in the processing chamber. For instance, the gasinjection source 230 can be located between first grid plate 210 andsecond grid plate 220.

As shown in FIG. 4, in some embodiments, the grid assembly 200. Forinstance, the gas injection source 230 can inject hydrogen gas into thespecies passing through the separation grid 200 at a location in theprocessing chamber below a first grid plate 210 and a second grid plate220.

At (314) of FIG. 2, the method can include exposing the workpiece to thehydrogen radicals. Exposing the workpiece to the hydrogen radicals canbe used to perform a variety of semiconductor fabrication steps.

For example, the hydrogen radicals can be exposed to a workpiece in theprocessing chamber for implementation of a variety of differentsemiconductor fabrication processes. For example, the hydrogen radicalscan be used for removal of a photoresist layer on the workpiece. Asanother example, the hydrogen radicals can be used to remove a residual(e.g., residual organic) on the workpiece to clean the workpiece. Asanother example, the hydrogen radicals can be used to assist withsilicon atom mobility and smoothing of the workpiece surface (e.g., athigh temperatures such as temperatures greater than about 400° C.). Asanother example, the hydrogen radicals can be used to at least partiallyremove a damaged silicon layer on the workpiece. As yet another example,the hydrogen radicals can be used to remove a suboxide layer on theworkpiece. The hydrogen radicals can be used to implement othersemiconductor process applications without deviating from the scope ofthe present disclosure.

In some embodiments, a metal-containing gas can be mixed with the one ormore hydrogen radicals to facilitate deposition of a thin metal film onthe workpiece. In some embodiments, the metal can be titanium. In someembodiments, the metal can be tantalum. In some embodiments, the metalcan be aluminum.

FIG. 5 depicts an example plasma processing apparatus 400 that can beused to implement processes according to example embodiments of thepresent disclosure. The plasma processing apparatus 400 is similar tothe plasma processing apparatus 100 of FIG. 1.

More particularly, plasma processing apparatus 400 includes a processingchamber 110 and a plasma chamber 120 that is separated from theprocessing chamber 110. Processing chamber 110 includes a substrateholder or pedestal 112 operable to hold a workpiece 114 to be processed,such as a semiconductor wafer. In this example illustration, a plasma isgenerated in plasma chamber 120 (i.e., plasma generation region) by aninductively coupled plasma source 135 and desired species are channeledfrom the plasma chamber 120 to the surface of workpiece 114 through aseparation grid assembly 200.

The plasma chamber 120 includes a dielectric side wall 122 and a ceiling124. The dielectric side wall 122, ceiling 124, and separation grid 200define a plasma chamber interior 125. Dielectric side wall 122 can beformed from a dielectric material, such as quartz and/or alumina. Theinductively coupled plasma source 135 can include an induction coil 130disposed adjacent the dielectric side wall 122 about the plasma chamber120. The induction coil 130 is coupled to an RF power generator 134through a suitable matching network 132. Process gases (e.g., an inertgas) can be provided to the chamber interior from gas supply 150 andannular gas distribution channel 151 or other suitable gas introductionmechanism. When the induction coil 130 is energized with RF power fromthe RF power generator 134, a plasma can be generated in the plasmachamber 120. In a particular embodiment, the plasma processing apparatus100 can include an optional grounded Faraday shield 128 to reducecapacitive coupling of the induction coil 130 to the plasma.

As shown in FIG. 5, a separation grid 200 separates the plasma chamber120 from the processing chamber 110. The separation grid 200 can be usedto perform ion filtering from a mixture generated by plasma in theplasma chamber 120 to generate a filtered mixture. The filtered mixturecan be exposed to the workpiece 114 in the processing chamber.

In some embodiments, the separation grid 200 can be a multi-plateseparation grid. For instance, the separation grid 200 can include afirst grid plate 210 and a second grid plate 220 that are spaced apartin parallel relationship to one another. The first grid plate 210 andthe second grid plate can be separated by a distance.

The first grid plate 210 can have a first grid pattern having aplurality of holes. The second grid plate 220 can have a second gridpattern having a plurality of holes. The first grid pattern can be thesame as or different from the second grid pattern. Charged particles canrecombine on the walls in their path through the holes of each gridplate 210, 220 in the separation grid. Neutral species (e.g., radicals)can flow relatively freely through the holes in the first grid plate 210and the second grid plate 220. The size of the holes and thickness ofeach grid plate 210 and 220 can affect transparency for both charged andneutral particles.

In some embodiments, the first grid plate 210 can be made of metal(e.g., aluminum) or other electrically conductive material and/or thesecond grid plate 220 can be made from either an electrically conductivematerial or dielectric material (e.g., quartz, ceramic, etc.). In someembodiments, the first grid plate 210 and/or the second grid plate 220can be made of other materials, such as silicon or silicon carbide. Inthe event a grid plate is made of metal or other electrically conductivematerial, the grid plate can be grounded.

As discussed above, a hydrogen gas can be injected into species passingthrough the separation grid 200 to generate one or more hydrogenradicals for exposure to the workpiece 114. The hydrogen radicals can beused to implement a variety of semiconductor fabrication processes.

The example plasma processing apparatus 400 of FIG. 5 is operable togenerate a first plasma 402 (e.g., a remote plasma) in the plasmachamber 120 and a second plasma 404 (e.g., a direct plasma) in theprocessing chamber 110. As used herein, a “remote plasma” refers to aplasma generated remotely from a workpiece, such as in a plasma chamberseparated from a workpiece by a separation grid. As used herein, a“direct plasma” refers to a plasma that is directly exposed to aworkpiece, such as a plasma generated in a processing chamber having apedestal operable to support the workpiece.

More particularly, the plasma processing apparatus 400 of FIG. 5includes a bias source having bias electrode 410 in the pedestal 112.The bias electrode 410 can be coupled to an RF power generator 414 via asuitable matching network 412. When the bias electrode 410 is energizedwith RF energy, a second plasma 404 can be generated from a mixture inthe processing chamber 110 for direct exposure to the workpiece 114. Theprocessing chamber 110 can include a gas exhaust port 416 for evacuatinga gas from the processing chamber 110.

FIG. 6 depicts a processing chamber 500 similar to that of FIG. 1 andFIG. 5. More particularly, plasma processing apparatus 500 includes aprocessing chamber 110 and a plasma chamber 120 that is separated fromthe processing chamber 110. Processing chamber 110 includes a substrateholder or pedestal 112 operable to hold a workpiece 114 to be processed,such as a semiconductor wafer. In this example illustration, a plasma isgenerated in plasma chamber 120 (i.e., plasma generation region) by aninductively coupled plasma source 135 and desired species (e.g., excitedinert gas molecules) are channeled from the plasma chamber 120 to thesurface of workpiece 114 through a separation grid assembly 200.

The plasma chamber 120 includes a dielectric side wall 122 and a ceiling124. The dielectric side wall 122, ceiling 124, and separation grid 200define a plasma chamber interior 125. Dielectric side wall 122 can beformed from a dielectric material, such as quartz and/or alumina. Theinductively coupled plasma source 135 can include an induction coil 130disposed adjacent the dielectric side wall 122 about the plasma chamber120. The induction coil 130 is coupled to an RF power generator 134through a suitable matching network 132. Process gas (e.g., an inertgas) can be provided to the chamber interior from gas supply 150 andannular gas distribution channel 151 or other suitable gas introductionmechanism. When the induction coil 130 is energized with RF power fromthe RF power generator 134, a plasma can be generated in the plasmachamber 120. In a particular embodiment, the plasma processing apparatus100 can include an optional grounded Faraday shield 128 to reducecapacitive coupling of the induction coil 130 to the plasma.

As shown in FIG. 6, a separation grid 200 separates the plasma chamber120 from the processing chamber 110. The separation grid 200 can be usedto perform ion filtering from a mixture generated by plasma in theplasma chamber 120 to generate a filtered mixture. The filtered mixturecan be exposed to the workpiece 114 in the processing chamber.

In some embodiments, the separation grid 200 can be a multi-plateseparation grid. For instance, the separation grid 200 can include afirst grid plate 210 and a second grid plate 220 that are spaced apartin parallel relationship to one another. The first grid plate 210 andthe second grid plate can be separated by a distance.

The first grid plate 210 can have a first grid pattern having aplurality of holes. The second grid plate 220 can have a second gridpattern having a plurality of holes. The first grid pattern can be thesame as or different from the second grid pattern. Charged particles canrecombine on the walls in their path through the holes of each gridplate 210, 220 in the separation grid. Neutral species (e.g., radicals)can flow relatively freely through the holes in the first grid plate 210and the second grid plate 220. The size of the holes and thickness ofeach grid plate 210 and 220 can affect transparency for both charged andneutral particles.

In some embodiments, the first grid plate 210 can be made of metal(e.g., aluminum) or other electrically conductive material and/or thesecond grid plate 220 can be made from either an electrically conductivematerial or dielectric material (e.g., quartz, ceramic, etc.). In someembodiments, the first grid plate 210 and/or the second grid plate 220can be made of other materials, such as silicon or silicon carbide. Inthe event a grid plate is made of metal or other electrically conductivematerial, the grid plate can be grounded.

The example plasma processing apparatus 500 of FIG. 6 is operable togenerate a first plasma 402 (e.g., a remote plasma) in the plasmachamber 120 and a second plasma 404 (e.g., a direct plasma) in theprocessing chamber 110. As shown, the plasma processing apparatus 500can include an angled dielectric sidewall 522 that extends from thevertical side wall 122 associated with the remote plasma chamber 120.The angled dielectric sidewall 522 can form a part of the processingchamber 110.

A second inductive plasma source 535 can be located proximate thedielectric sidewall 522. The second inductive plasma source 535 caninclude an induction coil 510 coupled to an RF generator 514 via asuitable matching network 512. The induction coil 510, when energizedwith RF energy, can induce a direct plasma 404 from a mixture in theprocessing chamber 110. A Faraday shield 528 can be disposed between theinduction coil 510 and the sidewall 522.

The pedestal 112 can be movable in a vertical direction V. For instance,the pedestal 112 can include a vertical lift 516 that can be configuredto adjust a distance between the pedestal 112 and the separation gridassembly 200. As one example, the pedestal 112 can be located in a firstvertical position for processing using the remote plasma 402. Thepedestal 112 can be in a second vertical position for processing usingthe direct plasma 404. The first vertical position can be closer to theseparation grid assembly 200 relative to the second vertical position.

The plasma processing apparatus 500 of FIG. 6 includes a bias sourcehaving bias electrode 410 in the pedestal 112. The bias electrode 410can be coupled to an RF power generator 414 via a suitable matchingnetwork 412. The processing chamber 110 can include a gas exhaust port416 for evacuating a gas from the processing chamber 110.

While the present subject matter has been described in detail withrespect to specific example embodiments thereof, it will be appreciatedthat those skilled in the art, upon attaining an understanding of theforegoing may readily produce alterations to, variations of, andequivalents to such embodiments. Accordingly, the scope of the presentdisclosure is by way of example rather than by way of limitation, andthe subject disclosure does not preclude inclusion of suchmodifications, variations and/or additions to the present subject matteras would be readily apparent to one of ordinary skill in the art.

1-18. (canceled)
 19. A method for processing a workpiece, the methodcomprising: generating one or more species in an inert gas in a firstchamber; filtering one or more ions in the first chamber using aseparation grid to generate a filtered mixture; injecting a hydrogen gasdownstream of the first chamber into the filtered mixture to generateone or more hydrogen radicals; exposing the workpiece to the one or morehydrogen radicals in a second chamber, the second chamber beingseparated from the first chamber by the separation grid.
 20. (canceled)21. The method of claim 19, wherein injecting a hydrogen gas downstreamof the first chamber into the filtered mixture to generate one or morehydrogen radicals comprises mixing hydrogen gas with neutral speciespassing through the separation grid.
 22. The method of claim 19, whereininjecting a hydrogen gas downstream of the first chamber into thefiltered mixture to generate one or more hydrogen radicals comprisesmixing hydrogen gas with neutral species in the separation grid.
 23. Themethod of claim 19, wherein the inert gas comprises helium.
 24. Themethod of claim 19, wherein the plasma is generated using an inductivelycoupled plasma source.
 25. The method of claim 19, wherein exposing theworkpiece in the second chamber to the one or more hydrogen radicals atleast partially removes a photoresist layer on the workpiece.
 26. Themethod of claim 19, wherein exposing the workpiece in a processingchamber to the one or more hydrogen radicals at least partially removesa residual organic material on the workpiece.
 27. The method of claim19, further comprising heating the workpiece to a temperature greaterthan about 400° C., wherein exposing the workpiece in the processingchamber to the one or more hydrogen radicals modifies silicon atommobility.
 28. The method of claim 19, wherein exposing the workpiece ina second chamber to the one or more hydrogen radicals at least partiallyremoves a damaged silicon layer.
 29. The method of claim 19, whereinexposing the workpiece in the processing chamber to the one or morehydrogen radicals at least partially removes a suboxide layer.
 30. Themethod of claim 19, further comprising mixing the one or more hydrogenradicals with a metal-containing gas to deposit a metal on theworkpiece.
 31. The method of claim 30, wherein the metal-containing gascomprises titanium.
 32. The method of claim 30, wherein themetal-containing gas comprises tantalum.
 33. The method of claim 30,wherein the metal-containing gas comprises aluminum.